How should a patient with a left ventricular ejection fraction of 46% be managed?

Management of Left Ventricular Ejection Fraction 46%

A patient with LVEF 46% has heart failure with mildly reduced ejection fraction (HFmrEF) and should be treated with SGLT2 inhibitors as first-line therapy, followed by consideration of ARNI or ARB plus MRA, along with beta-blockers if there is a history of myocardial infarction or acute coronary syndrome. 1, 2

Classification

• LVEF 46% falls into the HFmrEF category (LVEF 41-49%), which is distinct from HFrEF (LVEF ≤40%) and HFpEF (LVEF ≥50%). 1, 2
• This classification matters because device therapies like ICD and CRT are NOT indicated at this ejection fraction—they require LVEF ≤35%. 3
• Be aware that LVEF has substantial variability over time (within-person SD ~7.4%), and patients with HFmrEF have <25% probability of remaining in this category after 1 year. 4

Guideline-Directed Medical Therapy

Tier 1: SGLT2 Inhibitors (Strongest Evidence)

• Start dapagliflozin 10 mg daily OR empagliflozin 10 mg daily as foundational therapy for all patients with HFmrEF. 2
• SGLT2 inhibitors reduce heart failure hospitalization and improve quality of life through osmotic diuresis, improved myocardial efficiency, and favorable metabolic effects. 2
• This is now a Class I recommendation for heart failure with nonreduced ejection fraction (LVEF >40%). 2

Tier 2: Renin-Angiotensin System Blockade

• Consider sacubitril-valsartan (ARNI) starting at 24/26 mg or 49/51 mg twice daily, titrating to 97/103 mg twice daily. 2
• Alternative: Candesartan starting at 4-8 mg daily, titrating to 32 mg daily if ARNI is not tolerated or available. 2
• ACE inhibitors should be used if hypertension, diabetes, or chronic kidney disease is present, even though the primary indication here is the reduced ejection fraction. 5, 6, 7

Tier 3: Mineralocorticoid Receptor Antagonists

• Add spironolactone 12.5-25 mg daily (target 25-50 mg) OR eplerenone 25 mg daily (target 50 mg) if symptoms persist despite SGLT2i and ARNI/ARB. 2
• Monitor potassium and renal function closely, especially when combining with ACE inhibitors or ARBs. 5, 8

Beta-Blockers: Context-Dependent

• Beta-blockers (carvedilol, metoprolol succinate, or bisoprolol) are mandatory if:
  • History of myocardial infarction or acute coronary syndrome (continue for at least 3 years). 6, 7
  • Coronary artery disease is present. 6, 7
• Beta-blockers are NOT routinely required for HFmrEF without these conditions, unlike in HFrEF where they are universally indicated. 7

Device Therapy: Not Indicated

• ICD for primary prevention requires LVEF ≤35%—this patient at 46% does not qualify. 3
• CRT requires LVEF ≤35% plus additional criteria (NYHA class II-IV, QRS ≥150 ms, sinus rhythm)—not applicable here. 3
• If LVEF declines to ≤35% on repeat echocardiography despite optimal medical therapy, reassess for device eligibility. 3

Additional Considerations

Antiplatelet Therapy (If Atherosclerotic Disease Present)

• Aspirin 75-162 mg daily for patients with coronary or other atherosclerotic vascular disease. 5, 7
• Clopidogrel 75 mg daily may be added for up to 12 months post-ACS or post-PCI with stent. 5, 7

Obesity Management (If BMI ≥30 or BMI ≥27 with comorbidities)

• GLP-1 receptor agonists (semaglutide) or dual GLP-1/GIP agonists (tirzepatide) improve heart failure symptoms, functional capacity, and quality of life in patients with HFpEF and obesity. 9
• Weight loss of ~10% from baseline is the initial goal. 5

Monitoring and Follow-Up

• Repeat echocardiography in 3-6 months to assess for LVEF improvement (HFimpEF) or decline (HFrEF). 1
• If LVEF improves to >40%, continue all heart failure medications—discontinuation leads to relapse and recurrent dysfunction. 1, 3
• If LVEF declines to ≤40%, intensify therapy with full HFrEF guideline-directed medical therapy and reassess device eligibility. 1, 3

Common Pitfalls to Avoid

• Do not assume this patient needs an ICD or CRT—LVEF 46% is above the threshold for device therapy. 3
• Do not delay SGLT2 inhibitor initiation—this is now first-line therapy for HFmrEF. 2
• Do not discontinue medications if LVEF improves—this leads to recurrent heart failure. 1, 3
• Do not rely on a single LVEF measurement—variability is high, and serial assessments are essential. 4
• Do not use the term "diastolic heart failure" for patients with reduced LVEF—it creates confusion. 3